Clip from ABC News:
Anxious to avoid upsetting air travelers, NASA is withholding results from an unprecedented national survey of pilots that found safety problems like near collisions and runway interference occur far more frequently than the government previously recognized.
NASA gathered the information under an $8.5 million safety project, through telephone interviews with roughly 24,000 commercial and general aviation pilots over nearly four years. Since ending the interviews at the beginning of 2005 and shutting down the project completely more than one year ago, the space agency has refused to divulge the results publicly.
Just last week, NASA ordered the contractor that conducted the survey to purge all related data from its computers.
Link to article